rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/phonet/af_phonet.c

@@ -480,7 +480,7 @@ int __init_or_module phonet_proto_register(unsigned int protocol,
 	if (proto_tab[protocol])
 		err = -EBUSY;
 	else
-		rcu_assign_pointer(proto_tab[protocol], pp);
+		RCU_INIT_POINTER(proto_tab[protocol], pp);
 	mutex_unlock(&proto_tab_lock);
 
 	return err;
@@ -491,7 +491,7 @@ void phonet_proto_unregister(unsigned int protocol, struct phonet_protocol *pp)
 {
 	mutex_lock(&proto_tab_lock);
 	BUG_ON(proto_tab[protocol] != pp);
-	rcu_assign_pointer(proto_tab[protocol], NULL);
+	RCU_INIT_POINTER(proto_tab[protocol], NULL);
 	mutex_unlock(&proto_tab_lock);
 	synchronize_rcu();
 	proto_unregister(pp->prot);

net/phonet/pn_dev.c

@@ -276,7 +276,7 @@ static void phonet_route_autodel(struct net_device *dev)
 	mutex_lock(&pnn->routes.lock);
 	for (i = 0; i < 64; i++)
 		if (dev == pnn->routes.table[i]) {
-			rcu_assign_pointer(pnn->routes.table[i], NULL);
+			RCU_INIT_POINTER(pnn->routes.table[i], NULL);
 			set_bit(i, deleted);
 		}
 	mutex_unlock(&pnn->routes.lock);
@@ -390,7 +390,7 @@ int phonet_route_add(struct net_device *dev, u8 daddr)
 	daddr = daddr >> 2;
 	mutex_lock(&routes->lock);
 	if (routes->table[daddr] == NULL) {
-		rcu_assign_pointer(routes->table[daddr], dev);
+		RCU_INIT_POINTER(routes->table[daddr], dev);
 		dev_hold(dev);
 		err = 0;
 	}
@@ -406,7 +406,7 @@ int phonet_route_del(struct net_device *dev, u8 daddr)
 	daddr = daddr >> 2;
 	mutex_lock(&routes->lock);
 	if (dev == routes->table[daddr])
-		rcu_assign_pointer(routes->table[daddr], NULL);
+		RCU_INIT_POINTER(routes->table[daddr], NULL);
 	else
 		dev = NULL;
 	mutex_unlock(&routes->lock);

net/phonet/socket.c

@@ -679,7 +679,7 @@ int pn_sock_bind_res(struct sock *sk, u8 res)
 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == NULL) {
 		sock_hold(sk);
-		rcu_assign_pointer(pnres.sk[res], sk);
+		RCU_INIT_POINTER(pnres.sk[res], sk);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);
@@ -695,7 +695,7 @@ int pn_sock_unbind_res(struct sock *sk, u8 res)
 
 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == sk) {
-		rcu_assign_pointer(pnres.sk[res], NULL);
+		RCU_INIT_POINTER(pnres.sk[res], NULL);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);
@@ -714,7 +714,7 @@ void pn_sock_unbind_all_res(struct sock *sk)
 	mutex_lock(&resource_mutex);
 	for (res = 0; res < 256; res++) {
 		if (pnres.sk[res] == sk) {
-			rcu_assign_pointer(pnres.sk[res], NULL);
+			RCU_INIT_POINTER(pnres.sk[res], NULL);
 			match++;
 		}
 	}